[Federal Register Volume 63, Number 219 (Friday, November 13, 1998)]
[Proposed Rules]
[Page 63423]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-30334]
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Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
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Federal Register / Vol. 63, No. 219 / Friday, November 13, 1998 /
Proposed Rules
[[Page 63423]]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-134-AD]
RIN 2120-AA64
Airworthiness Directives; Bombardier Model CL-600-2B19 (Regional
Jet Series 100) Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Proposed rule; withdrawal.
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SUMMARY: This action withdraws a notice of proposed rulemaking (NPRM)
that proposed a new airworthiness directive (AD), applicable to certain
Bombardier Model CL-600-2B19 (Regional Jet Series 100) series
airplanes. That action would have required repetitive inspections of
the inboard and outboard flap actuators to measure the rotational
freedom of the actuator ball screw adjacent to the actuator housing,
and replacement of the flap actuators with new or serviceable
actuators, if necessary. Since the issuance of the NPRM, the Federal
Aviation Administration (FAA) has received new data pertaining to this
issue and is undertaking alternative rulemaking action. Accordingly,
the proposed rule is withdrawn.
FOR FURTHER INFORMATION CONTACT: Anthony E. Gallo, Aerospace Engineer,
Systems and Flight Test Branch, ANE-172, FAA, Engine and Propeller
Directorate, New York Aircraft Certification Office, 10 Fifth Street,
Third Floor, Valley Stream, New York 11581; telephone (516) 256-7510;
fax (516) 568-2716.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) to add a new airworthiness
directive (AD), applicable to certain Bombardier Model CL-600-2B19
(Regional Jet Series 100) series airplanes, was published in the
Federal Register on June 8, 1998 (63 FR 31140). The proposed rule would
have required repetitive inspections of the inboard and outboard flap
actuators to measure the rotational freedom of the actuator ball screw
adjacent to the actuator housing, and replacement of the flap actuators
with new or serviceable actuators, if necessary. That action was
prompted by issuance of mandatory continuing airworthiness information
by a foreign civil airworthiness authority. The proposed actions were
intended to prevent premature wear of the internal gears on the flap
actuators, which could result in complete disconnection of the actuator
gear set and a mechanical jam of the flap system. This condition could
cause structural damage and/or significant twist of a flap panel, which
could lead to reduced controllability of the airplane.
Actions Since Issuance of the Notice of Proposed Rulemaking (NPRM)
Since the issuance of the NPRM on June 2, 1998, the FAA has
received reports of six instances of jammed flap actuators on airplanes
that were in compliance with the requirements of that proposed AD. In
one case, a twisted flap was not detected prior to takeoff; in another
case, a twisted flap occurred upon deployment of flaps for landing. In
both cases, the airplanes were controllable and landed successfully.
These reports indicate that the replacement action specified by the
proposed rule is inadequate to address the unsafe condition.
As a result, the FAA has reconsidered its previous position on this
rulemaking action and issued AD 98-20-01, amendment 39-10767 (63 FR
49661, September 17, 1998), on September 11, 1998, to address the
unsafe condition. The actions of that AD require revising the
procedures in the FAA-approved Airplane Flight Manual for checking the
flap system. The amendment also requires revising the procedures in the
FAA-approved maintenance program, and performing follow-on actions, if
necessary. The actions specified in that AD are considered to be
interim action until final action is identified, at which time the FAA
may consider further rulemaking. The actions required by that AD are
intended to prevent an unannunciated failure of the flap system due to
a twisted outboard flap, which could result in a flap asymmetry, and
consequent reduced controllability of the airplane.
FAA's Conclusions
The FAA has determined that other rulemaking was required to
address the identified unsafe condition. In light of this other on-
going rulemaking activity, the FAA hereby withdraws the proposed rule.
Withdrawal of this NPRM constitutes only such action, and does not
preclude the agency from issuing another notice in the future, nor does
it commit the agency to any course of action in the future.
Regulatory Impact
Since this action only withdraws a notice of proposed rulemaking,
it is neither a proposed nor a final rule and therefore, is not covered
under Executive Order 12866, the Regulatory Flexibility Act, or DOT
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979).
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Withdrawal
Accordingly, the notice of proposed rulemaking, Docket 98-NM-134-
AD, published in the Federal Register on June 8, 1998 (63 FR 31140), is
withdrawn.
Issued in Renton, Washington, on November 4, 1998.
Vi L. Lipski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-30334 Filed 11-12-98; 8:45 am]
BILLING CODE 4910-13-U
